Challenge

Solution

Augmented this with intercooling or overspray to further boost processing capacity.

El Paso Energy

Chaco Cryogenic Processing Plant, Bloomfield, New Mexico.

The Chaco Cryogenic Processing Plant is situated in Bloomfield, 20 miles south of Farmington, New Mexico. The Chaco plant contains three refrigeration/de-ethanizer compressors and has a processing capacity of over 500 MMcf/d with natural gas liquid production of 50,000 Bbls/d. It gathers gas to be processed and routed to the El Paso gas pipeline system to be shipped to Western States and Northern Mexico.

El Paso Field Service executed a compression project to reduce field delivery pressures and increase production by an estimated 130 MMcf/d. This $50 million project included the installation of approximately 36,000 horsepower of new field compression and construction of an additional 56 miles of pipeline system. 10 new compressor units were added at five separate locations on its 5,500-mile system.

Even with this surge in capacity, however, Chaco suffered a crash in its gathering average high of 472 MMcf/d per quarter.

“Less than 400 MMcf/d would come when the temperature soared in summer,” said the plant manager. “This situation severely curtailed the output of the Chaco plant.”

Chaco engineers discovered that during hot weather, its combustion turbines produce up to twenty percent less power than in winter. This is due to the fact that the power output of a turbine depends on the flow of mass through it. That’s why on hot days, when air is less dense, power output falls off. As the pumps that pushed the gas into Chaco were powered gas turbines, the facility was not receiving the volume needed to satisfy demand.

Installation Challenges/Specifications

El Paso augmented the power of its two GE Frame 5 turbines by installing a MeeFog™ system. It uses high-pressure water pumps to pressurize demineralized water that flows through a network of stainless steel tubes to fog nozzle manifolds that are installed in the air stream inside the inlet duct. These nozzles atomize the water into fog droplets, which evaporate quickly and cool the air. By feeding cooler air into the CT, mass flow is increased, resulting in higher output.

Due to the climate of New Mexico, fogging is a seasonal activity. Between October and April the system isn’t needed much as temperatures remain low. In the other five months of the year, Chaco runs the fog system at maximum capacity to ensure that turbine power output remains high.

The fog system in use at the Chaco plant consists of a series of high-pressure (2000 psi) pumps (4 pumps total, one 3 hp pump, three 5 hp pumps, mounted on a skid an Allen Bradley PLC control system and an array of 224 nozzles. Each pump is connected to a fixed number of fog nozzles, representing one discrete stage of fog cooling (there are 7 stages in total). The pumps are turned on sequentially to control the amount of cooling. With seven stages, a 21°F drop in temperature is managed in 3°F increments. The Chaco plant requires 224 nozzles in each turbine. These nozzles have orifice diameters of 6 thousandths of an inch and produce fog droplets in the 10 micron range.

Putting it to the Test

The MeeFog cooling system has significantly boosted gas gathering at the facility during the summer.

“The Chaco plant has successfully harnessed a fog-based evaporative cooling to gather as much as 18 percent more gas during the hot summer days. This translates into as much as 35°F of cooling,” said the plant’s controls technician.

At Chaco, that means an extra 72 MMcf/d, depending on ambient conditions. This equates to $10,000-plus per day in terms of increased revenues. The Chaco plant also utilizes a fogging technique known as intercooling or over-spray. By purposefully injecting more fog into the inlet air stream than can be evaporated, turbine operators produce larger power boosts than would normally be associated with ambient conditions.

Unevaporated fog droplets are carried by the air stream into the first stages of the turbine compressor section, where the air is hot due to the work of compression. Higher temperatures increase the moisture holding capacity of air, so the fog droplets that would not evaporate in the inlet air duct, do so in the compressor. Once the fog evaporates in the compressor, it cools and makes the air denser. This reduces compressor outlet temperature and increases turbine efficiency, allowing fuel flow to be increased, thus generating more power. When applied at Chaco, this additional surge of power was accomplished without any problems with blade coating or compressor fouling. The Fog System Controls Technician at the plant noted that the compressor blades were far cleaner than before.

Chaco’s fog system has also brought about a reduction in emissions. By increasing the power output of the turbine, most people would expect that the level of NOx emissions would increase correspondingly. However, the opposite is true. At Chaco, increased power is achieved while lowering NOx emissions levels.

About Mee Industries Inc.

Mee Industries Inc. is the innovative, high technology corporation that provides highly customized, cost-effective fog solutions for a wide range of applications including gas turbine inlet air cooling. Founded in 1969 by former Cornell University Research Scientist, Thomas Mee Jr., today the company also specializes in revolutionary fog solutions for industrial humidification, outdoor air conditioning, greenhouse climate control, wine barrel humidification and unique special effects applications.

Renowned MeeFog™ turnkey solutions include meticulously designed and engineered, premium quality, integrated systems that deliver an unequaled combination of price and performance. Mee Industries products are backed by our experienced staff of technical personnel including leading researchers, project managers and engineers along with production and installation specialists. An active research and development division ensures our position of technological leadership in the fog system market. Mee Industries is a proud ISO 9001 certified corporation and manufactures components to meet exacting UL or CE requirements.

Mee Industries is a privately held company with corporate headquarters in Irwindale, Calfornia.